No, use the time box to help detect when things are not well understood and where clarity is needed. Time boxes bring rhythm

Sometimes, if the Product Owner and Scrum Master agree

A time box is a common practice underlying most agile processes especially, Scrum. Time boxing is a the closest thing in agile or scrum that we have to something that is clearly a best practice. Most managers or early adopters of Scrum wonder what they do to create a sense of urgency and the answer is simple “Time Box”.

In Scrum we have 6 formal timeboxes.

Release Planning

Sprint Planning

Sprint

Daily Standup

Sprint Review

Sprint Retrospective

Time boxes are a key element in Scrum. They form the a bases for how we manage the team’s energy. The general rule in using time boxes is to not adjust the time once you have set it. When the clock runs out the bell “dings” and things change.

#1 mistake those new to Scrum make is to adjust the sprint length to give the team more time to complete their work. Basic Scrum training should cover and provide an in depth explanation of why not to adjust the time box.